Shaft dislocation detector

ABSTRACT

A high speed rotating shaft is provided with an abrading collar. A contact assembly is mounted with the contacts thereof in juxtaposition to the collar. Upon displacement of the shaft from normal operating position, the collar abrades away one contact thus opening the detector circuit.

1711c States 1" 11i1tz a a1.

1 1 SHAFT DlSLOCATlON DETECTOR [76] Inventors: Clayton D. l-liltz, 102Coolidge Rd.,

. North Syracuse; Gordon 1L. Mount,

Gulf Bridge Rd., West Monroe; James W. Endress, 715 Scarboro Dr.,Syracuse, all of N.Y.

[22] Filed: Feb. 7, 1972 [21] App]. No.: 223,989

[52] US. Cl 340/271, ZOO/61.08, 200/6141, 340/282 [51] int. Cl. G081)21/00 [58] Field of Search 340/271, 269, 282, 340/267 R, 52 A;ZOO/61.08, D16. 13, 61.41, 61.42

[56] References Cited UNITED STATES PATENTS 3,321,045 5/1967 Veilleux340/52 A [451 Sept. 25, 1973 Maras 340/52 A Uribe 340/52 A PrimaryExaminer.lohn W. Caldwell Assistant ExaminerGlen R. Swann, lllAttorney-l-larry G. Martin, Jr. et a1.

[ ABSTRACT 5 Claims, 5 Drawing Figures Patented Sept. 25, 1973 3,761,911

- FIG. 5

' FIGI WWI/M14292; M

SHAFT DISLOCATION DETECTOR 7 BACKGROUND OF THE INVENTION A substantialnumber of devices have been designed and used for detecting displacementof a rotatable shaft or the like from normal operating position. Somesuch devices include a switch with the actuating member thereofpositioned to be engaged and operated by some member attached to theshaft upon displacement thereof. In one such device, a closedpressurized tube has an end located to be abraded away upon displacementof the shaft permitting the fluid pressure to escape and actuate apressure responsive switch.

All such known devices embody an expensive structural arrangement andare difficult to mount accurately in position. M

SUMMARY OF THE INVENTION A tubular contact member is fixedly mountedwith its inner end positioned in proximity to an abrading collar carriedby the rotating shaft. A second contact overlies the inner end of thetubular contact and is maintained in conductive relation thereto byspring pressure. The second contact is mounted on the inner end of asupporting member slidably mounted in the tubular contact. Upondisplacement of the shaft axially or radially, the collar abrades thesecond contact away and the supporting member, which is insulated fromthe tubular contact, is moved outwardly to assure complete opening ofthe detector circuit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing theorientation of the shaft and detector mechanism;

FIG. 2 is a lengthwise sectional view of the contact assembly prior tothe separation of the contacts thereof by abrading action of the shaftcollar;

FIG. 3 is a view similar to FIG. 2 showing one of the contacts abradedaway as a result of shaft displacement;

FIG. 4 is an enlarged view of the second contact of the pair wherein thecontact disc is attached to its supporting member by a fusable joint;and

FIG. 5 is a view taken on line 5-5, FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, l0designates a portion of a housing containing a journal bearing 11 and athrust bearing 12 in which the shaft 13 is journaled. The shaft isprovided with a radially extending collar 15, the peripheral surface 17of which is roughened as by being knurled. This surface, as shown inFIG. 1, extends in angular relation to the axis of the shaft 13,preferably at an angle of 45.

A contact assembly 20 is fixedly mounted in the flange 21 of a bracketformed with a second flange portion 22 fixed to the housing 10 as by capscrews 23. The contact assembly includes a first contact structureconsisting of a tubular contact member 25 threaded externally forthreaded engagement with the flange 21 of the bracket, and a lock nut 27is provided to secure the member 25 in adjusted position with the innerend thereof in proximity to the peripheral abrading surface 17 of thecollar 15.

A second contact structure consists of a disc-like portion 30 ofconductive material secured to the end of a supporting member in theform of stem 31 which is slidably mounted for axial movement in thetubular member 25. The supporting stem 31 is formed of conductivematerial and is insulated from the tubular member 25 by an insulatingsleeve 33. The inner end portion 35 of the supporting member 31 is ofreduced diameter as shown in FIG. 2.

The axial length of the supporting stem 31 exceeds the axial length ofthe tubular member 25, whereby the outer end portion of the supportingmember extends outwardly beyond the outer end of the tubular member 25.This extending portion is encircled by an insulating sleeve 37, which inturn is encircled by a helical compression spring 40. A washer 41 ofinsulating material is positioned between the outer end of the tubularmember 25 and the inner end of the spring 40. A cap 43 of insulatingmaterial is affixed to the outer end-of the support member 31, as bythreaded connection, and is engaged by the outer end of the spring 40.

In FIG. 2 it will be apparent that the spring 40 yield ingly urges thesupport member 31 outwardly and, accordingly, yieldingly holds thecontact disc 30 in overlying conductive engagementwith the inner end ofthe tubular member 25.

The tubular contact member 25 is mounted in conductive relation to themetal bracket 21, to which a terminal 47 is attached by one of the capscrews 23. A conductor 48 is attached to the outer end of the supportmember 31. A conductor 49 is connected to the terminal 47. Theconductors 48, 49 extend to the controller 50 energizing the driver 51,effecting rotation of the shaft 13. The conductors 48, 49 may also formpart of a circuit including an indicator lamp.

When the shaft 13 is rotating in normal operative position, theperipheral abrading surface 17 of the collar 15 is spaced slightly fromthe contact disc 30. Upon radial or axial displacement of the shaft, theroughened surface 17 of the collar is moved into engagement with thedisc 30 whereby the same is abraded away and is, therefore, separatedfrom the support member 31, and from engagement with the tubular contact25, whereupon, the spring 40 effects outward axial movement of thesupport member 31 as indicated in FIG. 3. This operation effects acomplete opening of the control circuit.

The mounting bracket for the contact structure 20 is formed, in theportion thereof intermediate the flanges 21, 22, with a stop tabextending in parallel spaced relation to the flange 21. The tab 60 isformed with an aperture for the free passage of the conductor 48. Thetab serves as a stop to limit outward movement of the support stem 31and the cap member 43 carried thereby upon the portion 30 of the secondcontact being abraded away.

The disc 30 may be formed integrally with the conductive support stem31, or it may be attached thereto by a fusable connection indicated at57, FIG. 4. The material at 57 may be of a form of a solder which willnot fuse at the operating ambient temperature, but will quickly melt bythe heat generated by abrading action of the collar 15, resulting inseparation of the disc from the support member 31.

This detector mechanism embodies, as will be apparent, a very simpleconstruction which may be fabricated at low cost. The various parts ofthe mechanism do not require precision machining. Upon the disc portion30 of the second contact structure being abraded away, the circuit 48,49 is positively opened. The reduced inner end portion 35 of the stem 31serves to prevent the stem from sticking in the tubular member of thefirst contact structure, upon the disc being abraded away. During theabrading operation, it might happen that the inner end of the stem 31would be formed with a radial burr which, if the inner end portion ofthe stem 31 was dimensioned close to the bore in the inner end of themember 25, or to the internal diameter of the insulating sleeve 33, thestem 31, with the burr thereon, might remain in contact with the member25 with the result that the circuit 48, 49 would not be opened. The borein the insulating sleeve 33 is slightly larger than the opening in theinner end of the member 25.

While a preferred embodiment of this invention has been described forpurposes of illustration, it will be appreciated that this invention maybe otherwise embodied within the scope of the following claims.

We claim:

1. Detector mechanism for detecting displacement of a rotating shaftfrom the normal operating position, said mechanism comprising a detectorcircuit, first and second normally closed contact structures connectedin said circuit, a radially extending collar fixed to said shaft, saidfirst contact structure including a tubular contact member of conductivematerial fixedly mounted with the inner end thereof positioned inproximity to said collar, said second contact structure including acontact portion formed of conductive material, spring means operable toyieldingly maintain said portion in overlying conductive engagement withthe inner end of said tubular contact, said collar being movable intoabrading engagement with said overlying portion of said second contactstructure upon displacement of said shaft from normal operatingposition, said overlying portion of said second contact structure beingseverable from said tubular contact member upon such abrading engagementby said collar.

2. Detector mechanism as set forth in claim 1 wherein said contactportion of said second contact structure is fixed to a supporting membermounted in said tubular contact for axial movement therein, said springmeans acting on said supporting member and yieldingly urging the same ina direction from the inner end of said tubular contact.

3. Detector mechanism as set forth in claim 2 wherein said supportingmember is formed of conductive material and means insulating saidsupporting member from said tubular contact member.

4. Detector mechanism for detecting displacement of a rotating shaftfrom normal operating position, said mechanism comprising a detectorcircuit, first and second normally closed contact structures connectedin said circuit, a radially extending collar fixed to said shaft, saidfirst contact structure including a tubular member of conductivematerial fixedly mounted with the inner end thereof positioned inproximity to said collar, a second contact structure including asupporting member of conductive material mounted in said tubular memberfor axial movement therein, a contact portion of conductive materialfixed to the inner end of said supporting member and overlying the innerend of said tubular member in confronting relation to said collar, saidsupporting member extending outwardly from the outer end of said tubularmember, a cap member fixed to the outer end of said supporting member inaxially spaced relation to the outer end of said tubular member, aspring encircling the outer end portion of said supporting member andbeing disposed intermediate the outer end of said tubular member andsaid cap, said spring being operable to yieldingly urge said supportingmember outwardly of said tubular member to maintain said contact portionof said second contact structure in overlying conductive engagement withthe inner end of said tubular member, and means insulating saidsupporting member and said spring from said tubular member, said contactportion of said second contact structure being severable from saidsupporting member upon said collar moving into abrading engagement withsaid contact portion.

5. Detector mechanism as set forth in claim 4 wherein said spring isoperable upon severance of said contact portion to move said supportingmember outwardly in said tubular member and stop means to limit theoutward movement of said support.

1. Detector mechanism for detecting displacement of a rotating shaftfrom the normal operating position, said mechanism comprising a detectorcircuit, first and second normally closed contact structures connectedin said circuit, a radially extending collar fixed to said shaft, saidfirst contact structure including a tubular contact member of conductivematerial fixedly mounted with the inner end thereof positioned inproximity to said collar, said second contact structure including acontact portion formed of conductive material, spring means operable toyieldingly maintain said portion in overlying conductive engagement withthe inner end of said tubular contact, said collar being movable intoabrading engagement with said overlying portion of said second contactstructure upon displacement of said shaft from normal operatingposition, said overlying portion of said second contact structure beingseverable from said tubular contact member upon such abrading engagementby said collar.
 2. Detector mechanism as set forth in claim 1 whereinsaid contact portion of said second contact structure is fixed to asupporting member mounted in said tubular contact for axial movementtherein, said spring means acting on said supporting member andyieldingly urging the same in a direction from the inner end of saidtubular contact.
 3. Detector mechanism as set forth in claim 2 whereinsaid supporting member is formed of conductive material and meansinsulating said supporting member from said tubular contact member. 4.Detector mechanism for detecting displacement of a rotating shaft fromnormal operating position, said mechanism comprising a detector circuit,first and second normally closed contact structures connected in saidcircuit, a radially extending collar fixed to said shaft, said firstcontact structure including a tubular member of conductive materialfixedly mounted with the inner end thereof positioned in proximity tosaid collar, a second contact structure including a supporting member ofconductive material mounted in said tubular member for axial movementtherein, a contact portion of conductive material fixed to the inner endof said supporting member and overlying the inner end of said tubularmember in confronting relation to said collar, said supporting memberextending outwardly from the outer end of said tubular member, a capmember fixed to the outer end of said supporting member in axiallyspaced relation to the outer end of said tubular member, a springencircling the outer end portion of said supporting member and beingdisposed intermediate the outer end of said tubular member and said cap,said spring being operable to yieldingly urge said supporting memberoutwardly of said tubular member to maintain said contact portion ofsaid second contact structure in overlying conductive engagement withthe inner end of said tubular member, and means insulating saidsupporting member and said spring from said tubular member, said contactportion of said second contact structure being severable from saidsupporting member upon said collar moving into abrading engagement withsaid contact portion.
 5. Detector mechanism as set forth in claim 4wherein said spring is operable upon severance of said contact portionto move said supporting member outwardly in said tubular member and stopmeans to limit the outward movement of said support.